It has previously been proposed to provide an ankle brace, or orthopedic apparatus including air inflatable bladders as shown in U.S. Pat. No. 4,280,489, in which the apparatus is intended to be worn within a separate shoe, and is inflatable with an external source of air pressure In addition, various arrangements have been proposed for ventilating shoes by circulating air through the shoes. Typical patents showing this type of arrangement include M. Dunker U.S. Pat. No. 2,552,711; D. W. Oltrogge, U.S. Pat. No. 2,560,591; A. C. Crawford, U.S. Pat. No. 2,676,422; C. N. Eaton U.S. Pat. No. 3,029,530; E. Karras, U.S. Pat. No. 3,331,146; and James Faiella, U.S. Pat. No. 4,414,760. These patents disclose the use of air pumping arrangement actuated by foot pressure for circulating air through a shoe, but do not include any orthopedic support functions.
In connection with athletic activities, such as football, basketball, tennis, or other vigorous activities, it is helpful if the footwear worn by the players gives full support to the foot and ankle to avoid sprains or subluxation, when vigorous movement is undertaken by the athlete. However, when the athletes are resting, on the bench, for example, it is undesirable to have the feet or ankles subject to substantial pressure, as this may inhibit circulation or the like during these rest periods.
Accordingly, a principal object of the present invention is to provide an athletic shoe which gives variable support to the foot and ankle, with increased support during periods when the user is active, and reduced or minimal support when the user is at rest. Another object of the invention is to provide an orthopedic shoe in which external air pumping arrangements are not required.